Intermittent Long Crank But Will Not Start Or Intermittent No Crank - keywords 2.2 2.2L 3.5L 3.9L BEC calibration code communication extended ground hard L61 LX9 LZ4 LZ9 nocrank nostart P0335 UBEC

This PI was superseded to update Recommendation/Instructions. Please discard PIC3649D.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Some customers may experience an intermittent no start condition that is not related to a battery charge condition. In some cases, the complaint may be described as a long crank concern. The Chevrolet Malibu equipped with 4 cylinder engines may possibly set code P0335.

Sometimes, the complaint may be the owner has to try and start the vehicle (cycle the key) several times before the vehicle will start.

It is important that at the time the vehicle is brought in for service that the complaint is understood.

When attempting to start the car, was it a cranks but will not start or was it a no crank?

Complaint of intermittent vehicle cranks/long crank but will not start:

1. Check that the ground stud nuts on the radiator support are tight. The terminal should not rotate.
2. Check that the main engine ground (located at the rear of the block above the transaxle) is tight. (G105) You will want to also make sure the terminal crimp is tight to the wire.
3. Remove the UBEC (Document ID # 1351208) and check that all the connectors underneath the UBEC are locked into position.
4. Reinstall the UBEC
5. For 4 cylinder VIN code F vehicles, check that the latest calibration for the vehicle loaded into the PCM
6. If the complaint is a long crank and then the engine starts, but runs roughly for a few seconds, check to see if the fuel pressure drops off when the engine is not running. If the pressure does drop off replace the fuel module assembly.

Complaint of intermittent no crank/ turn the key and nothing happens:

1. Check that G201/ G203 and G305 are secure.
2. Check high speed serial data circuit. (Document ID # 1465871) The connectors at the modules do not need to bebn removed from the module. The lock on each connector should be unlocked and then push the connector onto the module and then relock the connector at each module.
3. It the customer comments that there is no click or only one click noise heard when the key is turned. Then check G105 (the heavy engine ground located at the rear of the engine). The fastener may appear to be secure, but the ring terminal under the nut could be free to move. If this ground is secure then replace the UBEC.

If PCM code P1682 or SIR code B1370 is set, replace the UBEC.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.